An Observation Log of My Fiancée Who Calls Herself a Villainess is a oNA (web) anime that premiered in spring 2026, produced by Ashi Productions.

About the production: the story comes from a light novel, there are 12 episodes of about 24 minutes and its current status is "finished".

Its main genres are comedy, fantasy, romance and slice of life, with themes such as Heterosexual, Villainess, Male Protagonist and Royal Affairs.

On AniList, An Observation Log of My Fiancée Who Calls Herself a Villainess has an average score of 77%, a very good score, and appears on 34,409 users' lists.

Bertia is reincarnated into her favorite otome game—not as the heroine, but as the villainess engaged to the perfect Crown Prince Cecil! Fully aware that her role is to sabotage his future romance, she’s determined to bloom as a wicked flower and wither away according to the story. But no matter how hard she tries to scheme, her “evil” plans only make her more endearing! (Source: Crunchyroll) Note: Jishou Akuyaku Reijou na Konyakusha no Kansatsu Kiroku. was streamed 3 days in advance of the TV broadcast on Prime Video, and Crunchyroll beginning April 3, 2026. Regular broadcasting began on April 6, 2026.

Official synopsis from AniList.